Editing Soil erosion (section)

===Soil structure and composition===
[[File:Dead Sea Coastal Erosion March 2012.JPG|thumb|Erosional gully in unconsolidated [[Dead Sea]] (Israel) sediments along the southwestern shore. This gully was excavated by floods from the [[Judean Mountains]] in less than a year.]]
The composition, moisture, and compaction of soil are all major factors in determining the erosivity of rainfall. Sediments containing more [[clay]] tend to be more resistant to erosion than those with sand or silt, because the clay helps bind soil particles together.<ref>{{cite book|author=Mirsal, Ibrahim A.|chapter=Soil degradation|title=Soil Pollution: Origin, Monitoring & Remediation|publisher=Springer|year=2008|isbn=978-3-540-70775-2|page=100|chapter-url=https://books.google.com/books?id=Lr5bMTxom0IC&pg=PA100}}</ref> Soil containing high levels of organic materials are often more resistant to erosion, because the organic materials coagulate soil colloids and create a stronger, more stable soil structure.<ref name="Blanco-2010-p29" /> The amount of water present in the soil before the precipitation also plays an important role, because it sets limits on the amount of water that can be absorbed by the soil (and hence prevented from flowing on the surface as erosive runoff). Wet, saturated soils will not be able to absorb as much rainwater, leading to higher levels of surface runoff and thus higher erosivity for a given volume of rainfall.<ref name="Blanco-2010-p29" /><ref>{{cite book|author=Torri, D.|chapter=Slope, aspect and surface storage|editor=Agassi, Menachem|title=Soil Erosion, Conservation, and Rehabilitation|publisher=CRC Press|year=1996|isbn=978-0-8247-8984-8|page=95|chapter-url=https://books.google.com/books?id=-AqdSMDSUIgC&pg=PA95}}</ref> [[Soil compaction (agriculture)|Soil compaction]] also affects the permeability of the soil to water, and hence the amount of water that flows away as runoff. More compacted soils will have a larger amount of surface runoff than less compacted soils.<ref name="Blanco-2010-p29">{{cite book|author=Blanco, Humberto|author2=Lal, Rattan|name-list-style=amp|chapter=Water erosion|title=Principles of Soil Conservation and Management|publisher=Springer|year=2010|isbn=978-90-481-8529-0|page=29|chapter-url=https://books.google.com/books?id=Wj3690PbDY0C&pg=PA29}}</ref>